Thinking it over I realized that I've probably never lost a deer from cocking the rifle. I have had them skedaddle for other reasons just not for cocking. I learned long ago how to keep the rifle silent until it fires.
Still vivid in my memory are two bobcats I killed in the same week with my underhammer. The first one never heard a thing as it was walking directly away from me. In my comfortable wooden stand - maybe 8 feet up - I was dozing and comfy in the warm autumn woods when a slight sound brought me to attention. I saw the cat immediately and raised the underhammer .45 and cocked the hammer (no reaction from the cat) and fired. Actually that's when the "fun" started but that story's for another time. I got the cat.
A few days later I heard one walking past my stand on the left. This time when I cocked the hammer the cat froze momentarily then scooted a few feet behind a tree with several low limbs. The cat could see me but I couldn't see it. But as I stared at the tree I finally detected a bit of gray through a small hole formed by the fallen limbs. I shouldered the "already cocked" rifle aimed small and fired. Nothing moved so I got down and walked over to hole I'd fired through and there it was. It just happened to a part of the head I saw through the hole and now most of that was missing.
I could really shoot way back then but not so much now. I was always a methodical step by step shooter when shooting. But for some reason in the deer woods I tended to bring the rifle up knocking the frizzen stall off and firing as soon as the butt stock hit my shoulder (fitted me perfectly). It did keep me from second guessing the shot and aiming while shaking with buck fever.
With Eric's mention of dogs spoiling hunts that was a constant irritant when I lived in Virginia. But count me as a passionate dog lover who had several house dogs that we loved. A special one was a basset I raised from a pup until she died at 14. This experience left me with a special love for the big hearted breed.
In the woods going to my truck I was inundated by a swarm of dogs who shot past me without a glance in my direction. Well, true to form, a basset was running rear guard with the pack. But...BUT instead of following his cohorts he noticed me and happily came over to, absolutely, get petted and say "hi friend". To say he/she made my day is an understatement. Never had nor wanted a hunting dog, that's not my view of the species. Companions, rescuers, furry children are what they are.